president obama speaking out today on the tragedy, calling the attack, an act of terrorism. now with the latest news out of boston is fox news's craig boswell. >> the bombs detonated at the boston marathon used six liter pressure cookers packed with shards of metal, nail and ball bearings. they were place inside a black duffel bag and set on the ground. >> we had an attack. >> doctors removed sharp objects from lower extremities of victims. >> many have wound mostly in the lower part of their body, wound rated to the place effect of the bomb as well as small metallic fragments. >> the two bombs exploded about 12 seconds apart. the first near the finish line where 8-year-old martin richard was there to cheer on his father. the little boy was killed in the blast. when he ran back to his mother,wo siblings. bill richard issued a statement, saying we thank four family and friends and those we have never met for their thoughts a prayers. i ask you continue to pray for our family as we remember martin. the white house calls the attack an act of terror. meanwhile massachusetts gove